Pumping apparatus for artificial-silk spinning solutions



Aug. 26, 1930. i 5 sg 1,773,904

PUMPING APPARATUS FOR ARTIFICIAL SILK SPINNING SOLUTIONS Filed Feb. 25. 1928 2 Sheets-Sheet 1 27 16 F|Q l 2e 26 25 H Z 1%" H 6 20' Y //A(///Y/ )i 25 21 INVENTOR EDWARD KINSELLA,

Z4 0 By his Attorneys,

Au 26, 1930. E. KINSELLA 1,773,904

- PUMPING APPARATUS FOR ARTIFICIAL SILK SPINNING SOLUTIONS Filed Feb. 25. 1928 2 Sheets-$heet 2 i gw lllllll U \m U: 5 520 INVENTOR EDWARD KINSELLA By his Attorneys,

Patented Aug. 26, 1930 UNITED STATES PATENT OFFICE -EDWARD KINSELLA, OF SPONDON, NEAR DERBY, ENGLAND, ASSIGNOR T CELANESE CORPORATION OF AMERICA, A CORPORATION OF DELAWARE PUMPING APPARATUS FOR ARTIFICIAL-SILK SPINNING SOLUTIONS Application filed February 25, 1928, Serial No. 257,015, and in Great Britain December 21, 1927. I

This invention relates to new or improved vention COXHPIlSQS one or morepumpingunits each comprising a pump, a static measuring l'o device, and a pressure balance valve so. ar-

ranged and combined that thedelivery' side of the pump communicates with the inlet side of the static measuring device through one side of the'pressure balance valve the 1? motor member of which pressure balance valve is subjected on this side to the pressure of theinl'e't side of thestatic measuring device andon the other side to the pressure com-- monto the delivery side ofthe static measuring device and the spinning jet or et's or other point of use, which motor member carries or is arranged to operate valve member of the pressure balance valve to control the supply of spinning solution or other fluid to the pump from thesource of supply.

By'the term static measuring device Imean an orifice, capillary tube, constriction or equivalent device adapted to pass a given or measured volume of fluid by virtue of a given e press-uredifference existing between the inlet side and the outlet side of the said device The pump o'f'the pumping unitor of each the said balance valve being subjected on its 1 respective opposite sides to the before mentioned pressures and carrying or arranged to operate a valve member of the pressure-balance valve ('for instance a needle valvememher, or a double conical valve member, or a slide valve of the piston or other type); to-

control the supply of spinning solution or other fluid to the pump from the source of supply.

Or, for'instance, thepressure balance valve oil of the pumping unit or of each pumping unit may be'of thediaphragm type, the diaphragm of said balance valve being subjected on its respective opposite sides to the before mentioned pressures and carrying orarranged' to operate a valve member of the pressure balance valve (for instance aneedlevalve mem ber,'or a' double conical valve member, or a slidevalve ofthe piston or other type) to con trol the supply of spinning solution or other fluid to the pump from the source: of supply.

Any suitable means may be employed to provide a definite and substantially unvaryingpress'ure difference across'the staticmeasuring device (i. e. between the two sides thereof) ,irrespective of the pressure required toovercome the resistance of the point of use of the pumping unit,and for com pensating' for the drop in pressure occurring in. the spinning solution or other fluid in its passage through the static measuring device and thus by this compensation enabling a balance of pressures to be established against the respective sides of the motor member of the pressure balance valve. For instance the piston, diaphragm or other motor member of the pressure balance valve may be arranged to work against the pressureof a spring, or for instance the piston of the pressure'balance valve may be arranged to work against the force of gravity.

The pressure balance valve of the pumping unit or of each pumping unit is preferably so constructed and arranged to operate that its valve member entirely cuts oil the supply of fluid to the pump of the pumping unit when an excess out-of-balance pressure develops on the delivery side of the static measuring' device i. e. when, owing for instance to bad choking of the spinning jet or jets or other point of use, thepressure on the delivery sideof the static measuring device rises above thepressure capacity of the pump. By these means delivery from the pumping unit concerned is stopped (and prevented from giving incorrect delivery) until the cause of the out-o'f-balance condition is removed.v

Ifdesired the pressurebal'ance valve of the pumping unit or of each pumping unit may be. so constructed and arranged to operate that its valve member entirely cuts off the supply of fluid to the p.. 3 of the pun'iping unit when an exe :s out-o. Trice press .re develops on the inlet side of me static measuring device.

In performing the inventic ror the delivery of cellulose acc 1 solutions or fluids the v N ries with the temperature, and especially when delivering such solutions in the spinning of artificial silk, I preferably provide in association with the static measuring device a compensating device adapted to act under variation of temperature to control the orifice or other form of static measuring device so that the flow through the static measuring device, and hence the delivery from the pumping unit, remains uniform under variations of temperature. For instance, I may provide a small valve operated by a bi-metal strip or by a spirit capsule or any other thermally operated device to control the aperture of the orifice or other form of static measuring device employed.

\Vhen using the apparatus of the invention for the spinning of artilicial silk 1 preferably employ a number of tee pumping units fed irom the common source of supply, one

umping unit being preferably employed 1r ach artificial sill; spinning jet or nozzle.

The accompanying drawings serve to illustrate some forms or the invention, it being understood that they are given only by way of illustration and are in no way limitative.

Figure l is a view of one form of pumping unit in accordance with the invention, the pressure balance valve (shown in vertical section) in this form beingof the piston type, the piston of which operates a slide valve member of the piston type to control the supply of spinning solution to the pump from the source of supply. The form illustrated in this figure also comprises a valve operated by a bi-metal strip to control the aperture of the static measuring device, with a view to ensuring uniformity of delivery from the unitunder variation of temperature.

Figure 2 an elevation of the piston and slide valve member shown in Figure 1.

Figure 3 a vertical detail sectional view showing the static measuring device and aperture rontrolling valve of Figure 1 on an enlarged scale.

Figure l is a view of one form of pumping unit in accordance with the invention, the pressure balance valve (slrnvn in vertical section) in this form being the diaphragm type, the diaphragm of which is arranged to operate a double conical valve member to control the supply of spinning solution or other fluid to the pump from the :urce of supply. The form illustrated in this figure also comprises a valve operated by a spirit capsule to control the aperture of the static measuring device, with a view to ensuring uniformity of delivery under variation of temperatm'e.

F.' are 5 s a diagr mmatic ing appara ac plied to a metior or of artificial sill: by method off gramm tical; nuni similar to that s own fed with spinning sol on irom a common source of supply' two pumping units are shown in the section or portion of the spinning apparatus shown in th figure, it being understood that the a ")1 may comprise any desired number of pumping units similarly connected to and fed by the source of supply. The source of supply is not shown in this figure but may be any me s (for instance a pun'urv of the or piston type) suitable for suopl 1 the spinning s lution, und relative.=.y low pressure, to the puu'ip ng units.

Referring to Figure 1, 1 is the inlet from the source of supply. is the pump; this pump in the case illustrated being of the gear wheel type. 3 is the pressure balance valve, 4 is the static measuring device, this in the form illustrated being of the orifice type. The casing of the pressure balance valve is formed with two bores of different diameters, and has a piston 6 working in the lower and larger bore, and a hollow slide valve member 7 working in the upper and smaller bore. The casing may, if desired, be bored to a uniform diameter instead of to the two different diameters, but I have found the form shown to be advantageous when dealing with artificial sill; spinning solutions or other fluids requiring great sensitivity of control. The piston 6 divides the interior of the casing 5 into an upper chamber 8 and a lower cham' ber 9, and the valve member 7 is provided with the holes 10 communicating with its interior for enabling the piston G and slide valve member to move under variation of pressure. The upper chamber 8 communicates via the port 11 with the port 12, and hence with the static measuring device 4-, and with the outlet pipe leading to the spinview illustratto the invention ap i r the spinning J or evaporative rare showing diapumping u. s res 1, and 3,

mi we WliSGl ii) ning jet or jets or other point of use. The lower chamber 9 communicates via the port 14 with the delivery side of the pump 2 and via the port 15 with the inlet side of the static measuring device 4.

The inlet 1 from the source of supply communicates with the pump 2 via the annular groove 16 in the casing 5, the inclined annular groove 17 around the slide valve member 7, the annular groove 18 in the casing 5, and the inlet port 19 of the pump 2. By the positioning of the inclined groove 17 relatively to the annular grooves 16 and 18 the slide valve member 7 controls the supply of spinning solution or other fluid fed to the pump 2 from the source of supply.

..1 um. :n a other z7-Oliib ct use nee-s The static measuring device 4, shown on orifice constituting the true static. measuring device. It will be understood that the means.

shown in Figure 1 for mounting thev disc. 20 are. purely diagrammatic and that any suitable means. of mounting may be employed, for instance the disc may be held between an annular shoulder in the port 12 and a threaded ring, or it may be brazed or soldered to an annular shoulder in the port 12.

The piston 6 works against the pressureof the spring 22, the pressure of this. spring serving to establish the desired pressure (lit terence across the static measuring device l, and, by serving to compensate for the drop in pressure occurring in the spinning solution or other fluid in its passage through the static measuring device, enabling a balance of pressures to be established against the re spective sides of the piston 6..

In normal operation the spinning solution or other fluid passes from the source of supply (not shown), for instance from a gear wheel pump, under any suitable and relatively low pressure to the inlet pipe 1. From the inlet pipe 1 the fluid passes via the annular groove 16 in the casing 5, the inclined groove 17 around the slide valve member 7, the annular groove 18 in the casing 5, the port 19 and through the pump 2. From thence the spinning solution or other fluid passes via the port'll, lower chamber 9, port 15 and through the static measuring device 1; thence via the port- 12 to the upper chamber 8 and the. outlet pipe 13 and passes from the outlet pipe 13 to the spinning jet or jets or other point of use.

With the arrangement shown, substantially only the correct amount of spinning solution or other fluid is permitted to be fed to the static measuring device, as any pressure in the lower chamber 9 in excess of the pressure I in theupper chamber 8 e. the pressure of the fluid in the upper chamber 8 plusthe pressure of the spring 22) causes the piston 6 to move upwards and reduce the amount of fluid admitted to the pump 2 by restricting the aperture between the inclined groove 17 around the slide valve member 7 and the annular grooves 16 and 18 in the casing 5, the piston 6 and slide valve member 7 moving upwards until a. balance of pressures is created on the respective sides of the piston 6; conversely, if the resistance in the spinning jet or (due for instance to partial choking of the spinning jet or other point of use) it means that the pressurein the upper chamber 8 must also rise to overcome this resistance, this causes the piston 6 to move down and increase the aperture. between the inclined groove 17 and the annular grooves 16 and 18 (and thus ncreasing. the amount of fluid fed to the pump 2), the pistonv 6 and slide. valve member moving down until a balance. of pressures is created on the.

' respective sidesv of the piston 6,.the pressures of the fluid in the upper. and lower chambers being then higher than before. So long as the totalpressures against therespective sides of the piston 6 are equal, the pressure on the delivery side of the static measuring device is always. substantially that required to feed the measured quantity of fluid to the spinning jet or jets or other. point of use. In passing it should be noted that the supply of fluid from the inlet 1 to the pump 2 is at a maximum when the. upper and lower extremities of the inclined groove 17 arev in register respectively with the annular groove 16 and the annulargroove 18.

If an abnormal or excess out-of-balance the inlet port 19 of the pump 2, the pumping unit ceasing to deliver the spinning solution or other fluid to the spinning jet or jets or other point of use until the cause of the out-of-balance condition is removed. Conversely, if any abnormal or excess outof-balance pressure develops in the lower chamber 9, i. e. on the feed side of the static measuring device, the piston 6 rises suflicient 1y to move the inclined groove 17 out of register with the annular groove 18, thus cutting off communication entirely between the inlet pipe 1 (and hence with the source of supply) and the inlet port 19 of the pump 2, the pumping unit ceasing to deliver the j g soluticn or other fluid to 1- ning et or jets or other point of use until the causev of the on -of-balance condi ion is removed.

In the form shown in this figure means are provided to ensure oonst lit delivery from the pumping unit under variation of temperature when employing liquids {esp cial- 1y solutions of cellulose acetate or other cellulose derivatives in volatile solvents) the viscosity of which decreases with an increase of temperature. As such means a small valve restrict the aperture between the valve 23 and the orifice 21, and conversely any decrease in temperature causes the bi-metal strip 24 to lower the "alve 23 and enlarge the aperture between the valve and the orifice 21.

For starting up the unit when the communication between the inlet pipe 1 and the pump 2 is cut off by the valve member 7 (i. e. when the inclined groove 17 is out of register with either of the annular grooves 16 or 18), for instance when starting up the pumping unit initially, or after removal of the cause of either of the before mentioned exc'ess out-of-balance conditions, the screw valve member 25 is temporarily opened to allow fluid to pass from the supply pipe 1 via the annular groove 16 and the port 26 and port 19 t the pump Fluid so passing to the pump 2 passes from the pump via the port 14, the lower chamber 9, the static measuring device 4 and port 12 to the upper chamber 8, and thus moves the piston 6 to move the valve member 7 to open communi cation between the annular grooves 16 and 18 and the inclined groove 17 and put the pumping unit in operation.

The apparatus shown in Figure 1 is provided with a screw plug 27 provided with a channel 28. On first starting the pumping unit or on restarting the pumping unit after it has become emptied of fluid, the plug 27 may be unscrewed sufhciently tor the channel 28 to communicate with the atmosphere, thus enabling air in the unit to be displaced by the spinning solution or other fluid, and when the unit is full of fluid the plug 27 is screwed down to close the channel 28.

If desired the spring 22 may be omitted and a suitably heavy piston 6 be employed, in which case the weight of the piston (3 will serve to establish the desired pressure difference across the static measuring device, and, by serving to compensate for the drop in pressure occurring in the fluid in its passage through the static measuring device, onable a balance of pressures to be established on the respective sides of said piston.

Referring to Figure 4, this figure shows a similar form of pumping unit to that shown in Figures 1, 2 and 3 but the pumping unit shown in Figure 4 comprises a pressure balance valve of the diaphragm type, the diaphragm of which operates a double conical *alve men'iber to can all title )1; of fluid to the nnin of the n: auu, L. this figure the valve for controlling he static measuring device is operated by spirit capsule instead of. by a bi-metal strip.

Referring to Fig. 4, 1 is the inlet pipe leading from the source of supply. 2 is the pump, this pump in the case illustrated being of the gear wheel type. 3 is the pressure balance valve. 4 is the static measuring device, this in the form illustrated being of the orifice type. The casing 5 of the pressure balance valve 3 is provided with a bore in which the diaphragn'i (i is fitted, this diaphragm being held between the annular shoulder 7 and the threaded ring 9. The diaphragm divides the bore of the casing 5 into an upper chamber 10 and a lower chamber 11, and carries a member 12 which extenos upwards from the diaphragm through a bore 13 in the casing 5 and terminates in the double conical valve member 14. The bore 13 is provided with suitable annular grooves or the like 15, to prevent fluid lealring from the chamber 10 through the bore 13.

The lower chamber 11 communicates via the port 16 with the delivery side or" the pump 2, and also communicates with the static measuring device 4. The upper chamber 10 communicates via the port 17 with the outlet pipe 18A leading to the spinning jet or jets or other point of use, and via the port 17 and port 18 with the static measuring device 4, this device being constituted by a circular orifice 19 between the port 18 and the lower chamber 11. The inlet pipe 1 communicates via the port 20, the throat 21 and the inlet port 22 with the inlet side of the pump 2, and by the position of double conical valve memher 14 relatively to the throat 21 the supply of fluid to the pump 2 from the supply pipe 1 is controlled.

The diaphragm 6 works against the pres sure of the spring 23, the pressure of this spring serving to establish the desired pres sure difference across the static measuring oevice 4, and, by serving to compensate for the drop in pressure occurring in the spin ning solution or other fluid in its passage through the static measuring device, enabling a balance of pressures to be established against the respective sides of the diaphragm 6.

In normal operation the spinning solution or other fluid passes from the source of supply (not shown), for instance a gear wheel pump, under any suitable and relatively low pressure to the inlet pipe 1. From the inlet pipe 1 the fluid passes via the port 20, throat 21 and port 22, to the pump 2. From thence it passes via the port 16, lower chamber 11, through the static measuring device 4 to the port 18. From the port 18 the fluid passes to the outlet pipe 18A leading to the spinning jet or jets or other point of use and via the port 17 to the upper chamber 10.

With the arrangement shown, substantially only the correct amount of spinning solution or other fluid is permitted to be fed to the static measuring device, as any pressure in the lower chamber 11 in excess of the pres sure in the upper chamber 10 (i. e. the pressure in the upper chamber 10 plus the pressure of the spring 23) causes the diaphragm 6 to move upwards and reduce the amount of fluid admitted to the pump 2 by restricting the aperture between the lower cone of the double conical valve member 14 and the throat 21, the diaphragm 6 and double conical valve member 14 moving upwards until a balance of pressures is created on the respective sides of thediaphragm 6 conversely, if the resistance in the spinning jet or, jets or other point of use rises (due for instance to partial choking of the spinning jet or jets or other point of use) it means the pressure in the upper chamber 10 must also rise to overcome this resistance, this causes the diaphragm 6 to move down and increase the aperture between the lower cone of the double y conical valve member 14 and the throat 21 (and thus increase the amount of fluid fed to the pump 2) sufliciently to create a balance of pressures on the respective sides of the diaphragm 6, the pressures of the fluid in the upper and lower chambers being then higher than before. So long as the total pressures against the respective sides of the diaphragm 6 are equal, the pressure on the delivery side of the static measuring device is always substantially that required to feed the measured quantity of fluid to the spinjets or other point of'use.

ning jet or be noted that the upper cone of It should the double conical valve member 14 is normally positioned by the diaphragm 6 at a relatively large distance from the throat 21 and this upper cone only functions to restrict the throat 21 when an abnormalor excess outof-balance pressure develops in the upper of fluid to the pump 2, the pumping unit ceasing to deliver the fluid to the spinning jet or jets until the cause of the out-of-bal- 'ance condition is removed. Conversely, if an abnormal or excess out-of-balance pressure develops in the lower chamber 11 (i. e. on the feed side of the static measuring device) the diaphragm 6 causes the double conical valve member 14 to rise suificiently for the lower cone of said valve member to close the throat 21, and thus entirely stop the supply of fluid to the pump 2, the pumping unit ceasing to deliver the fluid to the spinning jet or jets or other point of use until the cause of the out-of-balance condition is removed.

In the form shown in this figure means are provided to ensure constant delivery from the pumping unit under variation of temperature when employing liquids (especially sodescend sufficiently for the.

lutions of cellulose acetate or other cellulose derivatives in volatile solvents) the viscosity which decreases with an increase of temperature. As such means a small valve memh r 2 erate by he collapsible metal cape to cei'itrol orifice 19 of asuring device. The valve mem,- ber 24 is fixed to the metal capsule '25 which contains a quantity of paraflin oil, methylated spirit, ether or other suitable liquid, the capsule bei fixed to the threaded rod 25 passing through the plug 27 in the casing By adjusting the nut 28 and the lock nut 29 the position of the valve member 24 may be adjusted or set relatively to the orifice 19. The valve member 24 is also fitted to or formed with a rod 30 which is fitted to a diaphragm 31, which diaphragm is exposed on one side to the pressure of the atmosphere and on the other side to the pressure of the fluid in the port 18, the diaphragm 31 thereby serving to obviate operation of the valve member 24 under changes of pressure lnthe spinning solution or other fluid. Should the temperature of the fluid in the pumping unit increase, the metal capsule 25 is expanded by the liquid contained therein and moves the valve member 24 to restrict the orifice 19 by the required amount; conversely, if the temperature of the fluid in the pumping unit decreases, the metal capsule 25 is contracted and increases the aperture between the valve member 24 and the orifice 19 by the required before mentioned excess or abnormal out-ofbalance conditions, the screw valve member 32 is temporarily opened to allow fluid to pass from the inlet pipe 1 via the port 33 and port 22 to the pump 2. Fluid so passing to the pump 2, passes from the pump 2 via the port 16, through the lower chamber 11, static measuring device 4, port 18 and port 17 to the upper chamber 10 b these means i r a operates the diaphragm 6 to open the aperture between the double conical valve member 14 and the throat 21 to put the pumping unit in operation.

If the double conical valve member 14 is replaced by a needle valve member (which replacement may conveniently be considered as equivalent to omitting the upper cone of the double conical valve member 14) the said needle valve member will function to control the supply of fluid to the inlet side of the pump 2 precisely in the manner in which the lower cone of the double conical valve member 14 functions. The needle valve member however will not function to cut olf the sup ply of fluid to the pump 2 when an abnormal or excess out-of-balance pressure develops on the delivery side of the static measuring device, but it may be so 'rositioned relatively to the throat 21 that it cuts oil entirely the supply of fluid to the pump 2 when an excess out-of-balance pressure develops on the feed side of the static measuring device.

Referring to Figure 1 is the supply pipe or header leading from the source of supply (not shown) for instance a gear wheel pump. 2, 2 are the respective pumping units, these pumping units being constructed and arranged to operate precisely as described with reference to Figures 1, 2 and 3.

The spinning solution passes from the source of supply (not shown) under any suitable and relatively low pressure, via the head er or supply pipe 1, the branch pipes 4:, 4, thence respectively through the pumping units 2, 2 to the spinning jets 5, 5*, these jets extruding the solution into the cells 6 of the spinning metier or cabinet where the artificial silk tilaiuen are formed by the evaporation of the volatile solvent in the known manner.

Should the supply of fluid from one or more ot the branch pipes 4. 4 to the pumps 3. 3 of the pumping units be cut off due to deve og'mient of excess out-of-balance pres sure in either the upper or lower chamber of the respective pressure balance valves of the pumping units. the delivery from the unit or units concerned will cease until the carse of the out-of-balance condition is removed.

VVhat I clam and desire to secure by Let ters Pa ent is:

1. Pumping apparatus for delivering artificial silk sp nning solutions or other fluids. compr s ng at least one pumping unit, itseli comprising a pump, an inlet port to said pump, a static measuring device and a pressure balance valve. whereof the delivery side of the pump communicates with the inlet side of the static measuring dev ce, said pressure balance valve comprising (a) a motor member subjected on the one side to the pressure of the inlet side of the static measuring device and on the other side to the pressure of the delivery side of the static measuring device and of the delivery from the pumping unit and (b) a valve member operative y connected to sa d motor member and arranged to control the inlet port to the pump. thereby contro ling the supply of fluid to said pump, and means for establishing a given pressure difference across the static measuring device and for compensating for the drop in pres sure of the fluid in its passage through said device, thereby enabling a balance of pressures to be established on the respective sides of the motor member of the pressure balance valve.

2. Pumping apparatus for delivering artificial silk spinning solutions or other fluids, comprising at least one pumping unit, itself comprising a pump, an inlet port to said pump, a static measuring device being an orifice of determined dimensions, and a pressure balance valve, whereof the delivery side of the pump communicates with the inlet side of the static measuring device, said pres sure balance valve comprising (a) a motor member subjected on the one side to the pressure of the inlet side of the static measuring device and on the other side to the pressure of the delivery side of the static measuring device and of the delivery from the pumping unit and (b) a valve member operatively connected to said motor member and arranged to control the inlet port to the pump, thereby controlling the supply of fluid to said pump, and means for establishing a given pressure difference across the static measuring device and for compensating for the drop in pressure of the fluid in its passage through said device, thereby enabling a balance of pressures to be established on the respective sides of the motor member of the pressure balance valve.

3. Pumping apparatus for delivering artificial silk spinning solutions or other fluids, comprising at least one pumping unit, itself comprising a pump. an inlet port to said pump. a static measuring device and a pressure balance valve. whereof the delivery side of the pump communicates with the inlet side of the static measuring device through one side of the pressure balance valve. said pressure balance valve comprising (a) a motor member subjected on the one side to the pressure of the inlet side of the static measuring device and on the other side to the pressure of the deliver side of the static measuring device and ot' the delivery from the pumping unit and (7)) a valve member operatively connect d to said motor member and arranged to control the inlet port to the pump. thereby controlling the supply of fluid to said pump. and means for establishing a given pressure difference across the static measuring device and for compensating for the drop in pressure of the fluid in its passage through said device, therebv enabling a balance of pressures to be established on the respective sides of the motor member of the pressure balance valve.

4. Pumping apparatus for delivering artficial silk spinning solutions or other fluids. comprising at least one pumping unit, itself comprising a pump, an inlet port to said pump, a static measurir 5 device being an orifice of determined dimens ons and a pressure balance valve, whereof the delivery side of the pump communicates with the inlet side of the static measuring device through one side of the pressure balance valve, said pressure balance valve comprising (a) a motor member subjected on the one side to the pressure of the inlet side of the static measuring device and on the other llL , balance valve.

side to the pressure of the delivery side of he t c measuring device and of the delivery from the pumping unit and a valve member operatively connected to said motor member and arranged .to control the inlet port to the pump, thereby, controlling the supply of are to said pump, and means for establishing a given pressure diflcrence across the static measuring device and for compensating for the drop in pressure or the fluidin its passage through said device, thereby enabling a balance of pressures to be established on the respective sides of the motor member of the pressure balance valve.

5. Pumping apparatus for delivering artificial silk spinning solutions or other ifluids, comprising at least one pumping unit, itself comprising a pump, an inlet port to said pump, a static measuring device and a pressure balance valve, whereof thedelivvery sideot the pump communicates with the inlet side of the static -measuri-ng device through one side of the pressure balance valve, said pressure balance valve "compris .ing (a) a;1n 0to.1 member subjected on the one side to the pressure of the inlet side of the static measuring device and on the other side to the pressure of the delivery side of the static measuring device and of the delivery from the pumping unit and (Zr) a valve member operatively connected to said motor member and arranged to control the inlet port to the pump, thereby controlling the supply offluid to said pump, and to close the inlet ;port to the pump when an excess out of balance pressure develops on the dclivery side of the static measuring device, and means for establishing a given pressure diflerence across the static measuring device and for compensating for the drop in pressure of "the fluid in its passage through said device, thereby enabling .abalance of pressures to be established on the respective sides of the motor member of the pressure 6. Pumping apparatus for delivering artificial .silk spinning solutions or other fluids, comprising at least one pumping unit, itself comprising a pump, an inlet port to said pump, a vstatic measuring device being an orifice ot determined dimensions and a pressure balance valve, whereof the delivery side of the pump communicates with the inlet side of the static measuring device through I one side of the pressure balance valve said pressure balance valve comprising a motor member subjected on the one side to the pressure of the inlet side of the static measuring device and on the other side to the pressure of the delivery s de of the statiemeasuring device and of the delivery from the pump ing unit and (b) a valve member operatively connected to sa d motor member and arranged to control the inlet port to the pump, thereby controlling the supply of fluid to excess out of balance pressure develops on 77 theinlet side of the static measuring device, andmeans for establishing a given pressure difference across the static measuring device and for compensating for the drop in pres sure'iof the fluid in its passage through said device, thereby enabling a balance of pressures to be established on the respective sides or the :motor member of the pressure balance valve.

7. Pumping apparatus according to claim 3 and comprising as the means for establishing a given pressure diderence across the static measuring device and for compensating vfor the drop in pressure of the fluid in :its passage through said device, a spring acting upon the motor member of the vpressure balance valve.

8.. Pumping apparatus according to claim 3 and wherein said pumping unit further comprises a compensating device vadapted to operate under variations of temperature to control the aperture of the static measuring device andv thereby secure constant flow throughsaid device under variations of tem- .perature.

9. Pumping apparatus according to claim 13 and wherein said pumping unit further comprises a compensating device adapted to Operate under variations of temperature to control the aperture of the static measuring device and thereby secure constant flow through said device under variations of temperature, said compensating device comprising a valvemember controlling the aperture of the static measuring device and a bi-met-al strip secured on the one end and carrying said Valve member on the other end. a

10. Pumping apparatus for deliverin artificial silk spinning solutions or other fluids, comprising at least one pumping unit, itself comprising a pump, an inlet port to said pump, a static measuring device being an orifice of determined dimensions and a pressure balance valve, whereof the delivery side of the pump communicates with the inlet side of the static measuring device through one side of the pressure balance valve, said pressure balance valve comprising (a) a piston motor member subjected on the one side to v the pressure of the inlet side of the static measuring device and on the other side to the pressure of the delivery side of the static .measuring device and of the delivery from the pumpingunit and (b) a slide valve member operatively connected to said piston moa tor member and arranged to control the inlet port to the pump, thereby controlling the supply of fluid to said pump and to close the inlet port to the pump both when an excess out ot'balance pressure develops on the delivery side of the static measuring device and when an excess out of balance pressure t le-- velops on the inlet side of the static measuring device, a spring actingiupon the piston motor member of the pressure balance valve by pressing against said motor member on the side thereof subjected to the pressure of the delivery side of the static measuring device, said spring serving to establish a given pressure dili'erence across the static measuring device and to compensate for the drop in pressure of the fluid in its passage through said device, thereby enabling a balance of pressures to be established on the respective sides of the piston motor member of the pressure balance valve.

11. Pumping apparatus according to claim 10 and wherein said pumping unit further comprises a compensating device adapted to operate under variations of temperature to control the aperture of the static measuring device and thereby secure constant flow through said device under Variations of tem perature.

12. Pumping apparatus according to claim 10 and wherein said pumping unit further comprises a compensating device adapted to operate under variations of temperature to control the aperture of the static measuring device and thereby secure constant flow thru said device under variations of temperature, said compensating device comprising a Valve member controlling the aperture of the static measuring device and a bi-metal strip secured on the one end and carrying said valve member on the other end.

13. Pumping apparatus for delivering artificial silk spinning solutions or other fluids,

comprising at least one pumping unit, it-

self comprising a pump, an inlet port to said pump, a static measuring device being an orilice of determined din'iensious and a pressure balance valve, whereof the delivery side of the pump communicates with the inlet side of the static measuring device through one side of the pressure balance valve, and where in said pumping unit comprises a gear wheel pump, a casing bored to two different intercomu'iunicating diameters, a moving member comprising a piston motor member operating in the larger bore of the casing and a hollow slide valve member operating in the sumllor bore in the casing, holes in s id moving member communicating between the interior of the slide valve member and the bores oi the casing for enabling the l'ilOVlng member to operate in said bores, passage-way in said casing and a disc formed. With an orifice of determined dimensions mounted in said passage-Way, said orifice constituting the static measuring device, an inlet port communicating between the larger bore and said passageway on the one side of said disc and a delivery port con'imunicating between the larger bore and said passage-Way on the other side of V I g between in said casing C0111 ery side of the gear Wiiee er bore at a point in comm i port, ort commur delivery port and the delive y pumping unit, an inlet port to the get pump and an annular groove ii bore communicat k ply port and an aimular groo bore communicating v- 'tli an inclined annular groove valve member, the slide valve i adapted to control the inlet port to wheel pump l "h nl' pump by the posi a, nular groove relatively to sain annular grooves in the smaller bore, and adapted to close the inlet port to the gear Wheel pump by moving the inclined an ular groove out of register with the nular grooves in the smaller bore both when an excess out of balance pressure develops on the delivery side of the static measuring device and When an excess out of balance pressure develops on the inlet side of the static measuring device, a spring arranged to a i et the said piston motor member on the sid thereof eX- posed to the pressure of the delivery port, i. e. the side subjected to the pressure of the delivery side of the static 1' ensuring device, said spring serving to establish a given pressure dillerence across the static measuring device and to compensate for the drop in pressure of the fluid in its passage through said device, therebv enabling a balance of pressures to be established on the respective sides of the said piston motor member.

14. Pumping apparatus according to claim 13 and wherein said pumping unit further comprises a compensating device itself co prising a valve member arranged to con '01 the aperture of the orifice in the disc, i. e. the aperture of the static measuring device, and a bi-metal strip secured to the casing on the one end and carrying said valve member on the other end, said compen. ing device being adapted to operate under variations of temperature to control the aperture of the static measuring device and thereby secure constant flow through said device under vari ations of temperature.

In testimony whereof I have hereunto subscribed my name.

EDYVARD KINSELLA. 

